The novel methane derivatives of the general formulae I and II (see below) according to the invention are thermotropic liquid-crystalline compounds; due to their molecular structure principle, which is novel for such compounds, they generally broaden the known range of liquid-crystalline substances by means of which mixtures having favorable applicational properties can be prepared.
By contrast, the molecules of mesogenic compounds which have hitherto achieved technical importance in display technology and as temperature displays have an elongate form (cf. K. J. Toyne in Thermotropic Liquid Crystals, John Wiley & Sons, Ed., G. W. Gray, 1987, pp. 28ff); these form nematic, cholesteric and smectic phases. In addition, thermotropic liquid-crystalline phases are formed by diskoid molecules (cf. C. Destrade et al., Mol. Cryst. Liq. Cryst. Vol. 106, p.121 (1984)).